Carl v



No. 6ll,388. Patented sept. 27, I898. c. v. PETRAEUS. LEAD PIBMENT AND METHOD OF MANUFACTURING SAME;

(Application filed Mar. 28, 1896.)

(SpecimnsJ .Ziwfnior: g g-i? 0M WWZL t me CARL V. PETRAEUS, OF JOPLIN, MISSOURI, ASSIGNOR TO OLIVER H. PIOHER,

or SAME PLACE. I

LEAD PIGMENT AND METHOD OF MANUFACTURING SAME.

SPECIFICATION forming part of Letters Patent No. 611,388, dated September 2'7, 1898.

Serial No. 584,519. ($peeimens.)

To aZZ whom it may concern.-

Be it known that I, CARL V. PETRAEUS, a citizen of the United States,residing in J 0plin, in the county of Jasper a'ndState of Missouri, have invented a certain new and Improved Lead Pigment and Method of Manu facturing the Same, of which the following is a true and exact description. I

My invention relates to the manufacture of a pigment, or rather the basis of a pigment, from lead; and particularly it relates to the manufacture of sublimed lead salts or compounds for use as a pigment.-

Heretofore ores or other material containing lead and sulfur have been treated in furnaces of various constructions,with the result of subliming or driving off asafumeagreater or less percentage of the metal present. This fume is of varying composition, in accordance with the treatment to which the metal-bearing material has been subjected. In some cases it consists of lead sulfid and lead sulfate, both in considerable proportion, and

some sublimed oxid of lead, while in other treatments it is essentially a sulfate of lead substantially free from lead sulfid, but mixed, as before, with some sublimed lead oxid. A small percentage of lead sulfit-e is also some timesfound in the fume, and it is rather the rule that such sublimed fumes should be mixed with fumes of other metals, notably zinc. For many years past these sublimed fumes have been used as the basis of a pigment. In such case the lead sulfite and sulfid, if present, are oxidized to the condition of a sulfate, and in this condition the mate rial is generally known by the name of sublimed white lead. The sublimed fume containing lead sulfid has also been used as a pigment basis, but is darkin color and has as yet not come into general use. While the I lead fumes of the character above described have been and are successfully used in the manufacture of paints, they are, as a rule, used in admixture with other pigments, and one reason for this is that the sublimed fumes, particularly in the form of sublimed white lead, are found to require a larger percentage of oil in grinding, and also, owing to certain physical peculiarities of the fume, paints made from it are found to be unsuitable for certain classes of work to which the ordinary commercial white lead is applied. ParticularlyIwould note that the sublimed'lead pigment has when applied a glossy appearance, which for some purposes is undesirable, and also that it does not lend itself to stencil- Work.

Now the object of my invention is to overcome the defects in the sublimed pigment which I have briefly noted above and to impart to it a character which more nearly assimilates it for use as a pigment to the ordinary white lead or leadcarbonate, while preserving its distinctive advantages as compared with the ordinary white lead; and my invention is based upon my discovery that the sublimed lead pigment when the combined sulfur and lead are chiefly in the form of a sulfate will be increased in density and at the same time so changed in character as to make a paint which will have a fiat finish and a paint which can be used for stencilwork and like purposes by subjecting it to a cintering treatment and then grinding the cintered product to. proper consistency for a pigment basis. In cintering the fumes the temperature employed should be one which will cause a coalescence of the particles of fume, but not sufficiently high to cause afu sion of the mass. I have obtainedexcell'ent results at a temperature of about 1,000 Fahrenheit, and I have ascertained that the temperature can be carried close to 2,000 Fahrenheit without causing the fusion of the mass and with the result of cintering the particles together. The best results I have obtained by the use of a temperature between 1,000 and 1,500 Fahrenheit. u

In carrying my process into effect I have used the Scotch-hearth furnace-such, for instance, as is shown in the drawings of Patent No. 223,931, granted to Lewis and Bartlett January 27, 1880-in which to smelt the ores or compounds containing lead and sulfur, collecting the fumes driven off from this furnace, which consist of a mixture of lead sulfid, lead sulfate, and oxid of lead. I have also reburned in a low-cupola blast-furnacesuch, for instance, as is shown in the drawings of Patent No. 496,038, granted to E. 0. Bartlett April 25, 1S93-the fume collected from the Scotch-hearth furnace, collecting the fume from the low-cupola furnace, which is essentially a mixture of lead sulfate and lead oxid, and have subjected this fume to the necessary cintering temperature and with the result of producing a sublimed lead pigment free from the objections heretofore existing, as above noted, and of course the fume collected from the low-cupola furnace, irrespective of the nature of the lead-bearing material fed to it, will be of the same character so long as said material contains both lead and sulfur.

In the drawings forming a part of this application, Figure 1 is a sectional view of a typical Scotch-hearth furnace; Fig. 2, a diagrammatic elevation showing a system of coolingflues and bag-screens such as I employ for cooling and screening the smoke and fume from the furnaces. Fig. 3 is a sectional view of a typical low-cupola furnace. Fig. 4 is a longitudinal sectional view, taken as on the line 2 2 of Fig. 5, of a furnace adapted for cintering the fume; and Fig. 5 is a cross-sectional elevation, taken as on the line 1 1 of Fig. 4, of this furnace.

A indicates the Scotch hearth, the offtakeflue being indicated at A.

G is the low-cupola furnace, its offtake-flue being shown at G. I

B indicates the inlet-opening of a coolingflue system 0, and to it is connected directly or indirectly the offtake-fiue of either of the furnaces A or G, the products of combustion being drawn through the flues by a suctionfan D and forced into a receptacle or receptacles, as E, from which they enter bags F, the gaseous matter escaping through the fabric of the bags and the fume and solid particle collecting in receptacle 1L.v Of course it will be understood that separate cooling and collecting devices, such as O E F, are provided for the furnaces A and G.

H is the cintering-furnace, the fume being charged into chamber H through door H H indicating a hearth onto which the cintered fume is drawn from chamber H, which chamber is heated by a furnace H 'of which H is the door and H H H flues surrounding chamber 11, as shown, and leading to a stack H The material resulting from the cintering treatment above described must in all cases be ground before it is fit for actual use as a pigment or can be properly mixed with oil for use as a paint. It is without further treatment an excellent paint basis; butit may be subjected to further treatments with a view of eliminating the zinc or other undesirable constituents which may be present or of converting the lead oxid into another compound, such as carbonate or sulfate of lead, and I will mention here that I have found a treatment which will convert the lead oxid into sulfate of lead to have a particular value, the product of such treatment consisting of sublimed and cintered lead sulfate in admixture with chemically-prepared lead sulfate having peculiarly valuable properties. This treatment, however, and the product resulting therefrom forms the subject-"matter of another application for Letters Patent, filed March 23, 1896, Serial No. 584,520, my present application relating to the broad process characterized by the cintering of the sublimed lead product and to the result of this cintering treatment, irrespective of the use to which it is afterward put or the modifications in its composition which may be considered desirable.

The furnace or other means used for cintering the fume as above described may be of any type and heated either internally or externally, my invention being in no wise concerned with the type of furnace used for this purpose, but merely with the temperature to which the material is subjected. So, also, it is not material in what particular variety of grinding-machine the cintered fume is reground. Any convenient apparatus may be used for this purpose.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In the manufacture of a lead pigment, the method which consists in treating material containing lead and sulfur in such manner as to drive off some or all of the lead in the form of a fume made up of lead in combination with sulfur and with oxygen and in which the lead and sulfur compounds are chiefly in the form of a sulfate and substantially free from carbon, sulfids, or other combustible substances, then collecting said fume, and then heating the collected fume to cause the particles of lead compounds to coalesce but without fusing the mass or substantially changing its chemical character.

2. In the manufacture of a lead pigment, the method which consists in treating material containing lead and sulfur in such manner as to drive off some or all of the lead in the form of a fume made up of lead in combination with sulfur and with oxygen and in which the lead and sulfur compounds are chiefly in the form of a sulfate and substantially free from carbon, sulfids, or other combustible substances, then collecting said fume, then heating the collected fume to cause the particles of lead compounds to coalesce but without fusing the mass or substan'tially changing its chemical character, and then grinding the cintered particles in order to adapt them for use as a pigment.

3. In the manufacture of lead pigment, the method which consists in treating material containing lead and sulfur in such manner as to drive off some or all of the lead in the form of a fume made up of lead in combination with sulfur and with oxygen, then collecting said fume, then reburning said fume to produce a fume compound consisting essentially of lead sulfate and lead oxid, and

finally heating the said reburned fume t0 chiefly in the form of lead sulfate, the particause the particles of lead compounds to'cocles of the sublimate being hard, dense and alesce but Without fusing the mass or subcintered together, as specified.

' stantially changing its chemical character. CARL V. PETRAEUS.

4. As a new article of manufacture the de- Witnesses: scribed pigment basis consisting in whole, or CHARLES F. ZIEGLER,

.in part, of a sublimate of lead and sulfur, FRANCIS T. CHAMBERS. 

